I understand. Really strange since there are no web applications offered on 4dots.com. Is there any kind of information you get when you visit 4dots.com? Perhaps a firewall rule identification ID, or anything? We could get in contact with the company or whoever is responsible for the ruleset.
Perhaps we will change the CDN host to .mobileread.com. Only then we'll need to also adjust the cookie code to avoid unnecessarily sending it over for static content. Messing with cookies is always risky business though.